Bug 1463819: Account for the possibility of SyncAttributesToWidget destroying the window. r=enn

MozReview-Commit-ID: 8O3We8wnSGk

xpfe/appshell/nsXULWindow.cpp

@@ -448,9 +448,6 @@ NS_IMETHODIMP nsXULWindow::Create()
 
 NS_IMETHODIMP nsXULWindow::Destroy()
 {
-  MOZ_DIAGNOSTIC_ASSERT(!mSyncingAttributesToWidget,
-                        "Destroying the window from SyncAttributesToWidget?");
-
   if (!mWindow)
      return NS_OK;
 
@@ -1124,13 +1121,15 @@ void nsXULWindow::OnChromeLoaded()
     mChromeLoaded = true;
     ApplyChromeFlags();
     SyncAttributesToWidget();
-    SizeShell();
-
-    if (mShowAfterLoad) {
-      SetVisibility(true);
-      // At this point the window may have been closed during Show(), so
-      // nsXULWindow::Destroy may already have been called. Take care!
+    if (mWindow) {
+      SizeShell();
+      if (mShowAfterLoad) {
+        SetVisibility(true);
+      }
     }
+    // At this point the window may have been closed already during Show() or
+    // SyncAttributesToWidget(), so nsXULWindow::Destroy may already have been
+    // called. Take care!
   }
   mPersistentAttributesMask |= PAD_POSITION | PAD_SIZE | PAD_MISC;
 }
@@ -1550,9 +1549,6 @@ void nsXULWindow::SyncAttributesToWidget()
   if (!windowElement)
     return;
 
-  AutoRestore<bool> scope { mSyncingAttributesToWidget };
-  mSyncingAttributesToWidget = true;
-
   MOZ_DIAGNOSTIC_ASSERT(mWindow, "No widget on SyncAttributesToWidget?");
 
   nsAutoString attr;
@@ -2426,7 +2422,9 @@ nsXULWindow::BeforeStartLayout()
   ApplyChromeFlags();
   LoadPersistentWindowState();
   SyncAttributesToWidget();
-  SizeShell();
+  if (mWindow) {
+    SizeShell();
+  }
   return NS_OK;
 }
 

xpfe/appshell/nsXULWindow.h

@@ -179,7 +179,6 @@ protected:
    // mDestroying is used to prevent reentry into into Destroy(), which can
    // otherwise happen due to script running as we tear down various things.
    bool                    mDestroying;
-   bool                    mSyncingAttributesToWidget = false;
    bool                    mRegistered;
    uint32_t                mPersistentAttributesDirty; // persistentAttributes
    uint32_t                mPersistentAttributesMask;